Advanced fluid filtration applied to a modular platform for complete wastewater treatment

The core of the proposed research and development project involves the design, engineering, construction, and installation of a pilot-scale prototype for separating suspended solids from the effluent of existing wastewater treatment plants (WWTPs), its operational testing under real-world conditions at an actual WWTP, and the optimization of prototype technologies for the polishing of municipal wastewater—specifically for the stage preceding tertiary and, above all, quaternary treatment. The vast majority of existing WWTPs employ the activated sludge process, relying on gravity separation to separate activated sludge from treated water. Although alternative membrane separation ensures high-quality effluent regarding suspended solids concentration (below 2 mg/l), it entails high operating costs due to the aeration required for the mechanical cleaning of membrane modules, the chemical cleaning of membranes, and higher expenses for technical and process supervision. The project aims to develop and pilot-test a specialized, innovative separation technology based on fluidized-bed filtration—using a filter medium composed of polymer elements made from hybrid micro- and nanofiber materials, supplemented by the modification of the water's physical properties—to achieve high treatment efficiency at low operating (energy) costs. The polymer elements are based on materials research conducted at TUL, which focused on developing innovative biomass carriers for tertiary and—more importantly—quaternary wastewater treatment stages (specifically for post-denitrification, hybrid post-nitrification reactors, and the polishing of quaternary oxidation stage effluents to facilitate the oxidative degradation of micropollutants; see Havlíček, Dufek, Lederer, *Vodní hospodářství*). Previous applied research revealed that hybrid carriers featuring a micro/nanostructure are highly effective at capturing suspended solids (activated sludge particles) from the water. This finding prompted the proposal to utilize these materials in a different context: the efficient filtration of effluent from existing secondary clarifiers.